As mobile telephone service subscribers immensely increase, demand for Mobile Telephone Numbers (MTNs) and amount of subscribers' data to be handled, such as billing data, grow hugely corresponding to the increase of the mobile telephone service subscribers. The MTNs and the subscribers' billing data are grouped, managed and/or stored by billing or management systems located according to geographical boundaries. For example, a billing system specific to the Northeast area puts together and manages MTNs having the Northeast area code (e.g. New York City 212) and billing data for the MTNs having the Northeast area code. Correspondingly, other areas such as the Midwestern and the West coast have their own billing systems to manage MTNs having their own area codes and billing data for the MTNs having the area codes. Billing data for MTNs having New York City area code (212) are stored and managed by the Northeast billing system, whereas billing data for MTNs having Los Angeles area code (213) are managed and stored by the West Coast billing system.
Such a geographical restriction on MTNs of the subscribers' mobile telephones and management of billing data causes inconveniences to new or existing mobile telephone subscribers. When a new subscriber, a resident at Los Angeles, opens a mobile telephone at a Point-Of-Sale (POS) of in a different non-residence location, e.g. at store when visiting Washington D.C., the new subscriber has no choice but to have the area code of Washington D.C. (202), even if he wants to have the Los Angeles area code (213) as the area code of his mobile phone, since MTNs of mobile telephone subscribers are managed depending upon the geographic area of POS where the mobile telephone account is opened. Such inflexibility in choosing MTNs is the case with existing mobile telephone subscribers, even when the existing mobile telephone subscribers open another mobile telephone number under their existing mobile telephone accounts.
Moreover, the geography-based management of billing data cannot meet the mobile telephone subscriber's needs for receiving charges for plural mobile telephones that are opened as one bill under the name of the subscriber and for sharing minutes between the plural mobile telephones. For example, a new or existing subscriber having his own MTN with the NYC area code (212), who has plural mobile telephones under his or her name, wants to receive and pay one bill for charges for the plural mobile telephones, including a mobile telephone having the LA area code (213). However, since the billing data for the mobile telephone having the LA area code (213) is stored and managed by the billing system located in the West Coast area, and the billing data for the mobile telephone having the NYC area code (212) is stored and managed by the billing system located in the Northeast area, the billing data for both telephones cannot be put together and charged under one subscriber account. This collective billing demand is desperate in the case of companies of which employees are scattered all over a variety of geographic areas.
Hence, a need exists for management of MTNs and billing data associated with the MTNs regardless of the geographic boundaries of the mobile telephone subscribers. Another need exist for allowing billing data of MTNs that are stored in a plurality of data servers depending upon geographical areas to be shared among the data servers.